Various types of fuse units to be directly attached to batteries have been conventionally proposed (see Patent Literature 1). FIG. 1 shows a related art of such fuse units. In FIG. 1, a fuse unit 100 is fixed to a battery post 102 of a battery 101 via a battery terminal 103. The fuse unit 100 includes a unit body 105 and a battery cover 140. The unit body 105 includes a bus bar 110 being a conductive metal plate and an insulating protection 120 provided on an outer surface of the bus bar 110 by insert molding.
The battery terminal 103 is connected to the bus bar 110. The bus bar 110 has: a power supply connection portion 111 receiving power supply from the battery post 102; a starter motor connection portion 112 to which a starter motor terminal 130 is connected; an alternator connection portion 113 to which an alternator terminal 131 is connected; load connection portions (not illustrated) to which load terminals (not illustrated) are respectively connected; an alternator fuse 115 disposed between the power supply connection portion 111 and the alternator connection portion 113; and multiple load fuses 116 each disposed between the power supply connection portion 111 and a corresponding one of the load connection portions (not illustrated).
The unit body 105 has an L-shape bent at right angles and is disposed along a top surface 101a and a side surface 101b of the battery 101. The unit body 105 is thus installed in a peripheral space of the battery 101 which is allotted for the fuse unit 100.
The battery cover 140 has an almost box shape whose bottom is opened. The battery cover 140 includes a cover body 141 and a lid 143 turnably supported by the cover body 141 via a hinge 142. A side surface cover 144 is provided to extend in a portion below one side end of the cover body 141. The side surface cover 144 functions as a slide guide when the battery cover 140 is mounted by sliding. Specifically, in the mounting of the battery cover 140, the battery cover 140 is slid on the unit body 105 from above with the side surface cover 144 used as the slide guide. The battery cover 140 covers the battery post 102, the battery terminal 103, and the unit body 105 from above and from sides. The battery cover 140 serves to provide an insulating function, a waterproof function and the like of the fuse unit 100.